An air conditioner for a vehicle is an apparatus which inhales indoor air and outdoor air of a vehicle and cools or heats the inhaled air through a heat exchanger and blows the heat-exchanged air to the interior of the vehicle so as to maintain the interior of the vehicle at a proper temperature in the summer season or the winter season or to secure a driver's front and rear visual fields by removing frost from windows of the vehicle in the rainy season or the winter season.
In the meantime, the interior of the vehicle is easy to be polluted because it is small and sealed, and is more polluted because of fine dust and various pollutants in downtown areas. Particularly, due to a continuous increase in a distribution rate of vehicles and an increase of the time when people are inside vehicles, studies for maintaining comfort of the interior of the vehicle have been making.
As an example for showing purification of the interior of a vehicle, Korean Patent Laid-open No. 10-2004-97758 discloses an air cleaner for a vehicle which sterilizes microorganisms collected during an air cleaning process so as to make flow in cleaner air to the interior of the vehicle. As shown in FIG. 1, the air cleaner for a vehicle includes: a case 50 which has a suction port 51 and an exhaust port 52; a first filter 60 which is mounted in rear of the suction port 51 to collect foreign matters or dust; an electrostatic dust collector 70 for adsorbing fine dust using electrical discharge; a second filter 90 which is mounted in front of the exhaust port 52 of the case 50 and is coated with photocatalyst to decompose organic materials and sterilize harmful microorganisms; and an ultraviolet lamp 80 which is mounted between the electrostatic dust collector 70 and the second filter 90 to activate the photocatalyst of the second filter 90.
Such an air cleaner for the vehicle sterilizes harmful microorganisms using the photocatalyst activated by ultraviolet rays of the ultraviolet lamp and removes causes of bad smell through decomposition of organic materials. The air flown in through the suction port 51 of the case 50 is filtered while passing through the first filter 60. The first filter 60 mainly filters coarse-grained dust. The first filtered air flows into the electrostatic dust collector 70. When electricity is supplied through a power supply unit 73, fine dust particles charged by a discharge electrode 71 are adsorbed to a dust collection electrode 72. Therefore, the fine dust passing the first filter is removed by the electrostatic dust collector 70. While the air passing through the electrostatic dust collector 70 flows to the second filter 90, microorganisms, such as germs or molds, contained in the air are sterilized by ultraviolet rays radiated from the ultraviolet lamp 80. Moreover, the second filter 90 decomposes organic materials, such as ammonia, using the photocatalyst activated by the ultraviolet rays radiated from the ultraviolet lamp 80 so as to prevent generation of bad smell and to sterilize and remove harmful microorganisms, such as germs or molds, contained in the collected fine dust. Therefore, the air exhausted through the exhaust port 52 of the case 50 becomes purified air from which dust and harmful microorganisms are removed.
That is, the air cleaner for the vehicle uses filters of various kinds to which fine dust is collected or complexly uses the filters and an ultraviolet lamp for sterilization.
However, the filters for collecting fine dust are divided into a filter for filtering particles above specific diameter using a dust filter, a filter for collecting germs, molds and bad smell generation factors using an activated carbon filter, and a filter for collecting dust after discharging electricity so that dust has specific electric charge.
The first and second filters need to be replaced with new filters because removing dust by dust collection. However, the third filter of the electrostatic dust collection type does not need to be replaced with a new one and can effectively remove even small-sized particles.
FIG. 2 illustrates dust collection of the electrostatic dust collector 70 which is the filter of the electrostatic dust collection type. In FIG. 2, the electrostatic dust collector 70 includes: an electric charge unit 71 which has a discharge board 71a and a discharge pin 71b for charging dust (D) with electricity by corona discharge; and a dust collection unit 72 for collecting the dust (D′) charged through the electric charge unit 71.
However, the electrostatic dust collector illustrated in FIG. 2 generates electromagnetic noise and ozone at a sharp end portion of the electric discharge pin due to electric charge by corona discharge. Because electromagnetic noise interrupts operation of various devices inside the vehicle and ozone is harmful to human bodies, the electrostatic dust collector needs additional means for removing electromagnetic noise and ozone.
Korean Patent No. 10-0505276 (entitled “Air cleaner for vehicle published on Nov. 18, 2004)